As shown in FIG. 1a, according to 3G WCDMA (Third Generation Wideband Code Division Multiple Access), in communicating via wireless communication, a mobile user equipment (UE) 18 interfaces with a UTRAN (universal mobile telecommunications system (UMTS) terrestrial radio access network) Node B 17 (also sometimes called a base station) over a so-called Uu interface. The UTRAN Node B in turn communicates with a UTRAN radio network controller (RNC) 11 over a so-called Iub interface, and the RNC communicates with a core network (CN) entity, either a mobile switching center (MSC) or a serving GPRS (general packet radio system) support node (SGSN), over a so-called Iu interface, and also communicates with other RNCs over a so-called Iur interface. The Iu interface is more specifically either an Iu circuit-switched interface IuCS between a UTRAN RNC and an MSC, or an Iu packet-switched interface IuPS between a UTRAN RNC and an SGSN.
The 3GPP document E-DCH (enhanced dedicated channel) TR: 3GPP TR R3.015 V0.2.1 (2004-12) FDD Enhanced Uplink: UTRAN Iub/Iur Protocol Aspects (Release 6, Section 6.3.2) adequately describes the problem and opens issues related to the present invention. Section 6.3.2 of the above document is summarized below.
For delay-sensitive conversational class flows, it may be desirable to limit the maximum number of retransmission attempts to only a few. This is particularly true for 10 ms TTI (transmission timing interval), where the payload may lose its relevance to the application in case it is delayed for more than one or two HARQ (hybrid automatic repeat request) retransmissions.
The Node B may detect the failure through the discontinuation of the retransmission events.
At the time of this invention, the following items were of interest:                Details on the way the HARQ Decoding Failure Indication is signalled. For example, this indication could be a specific value of the number of HARQ retransmissions field (e.g. 15) inserted into a UL (uplink) data frame with TB block size set to zero. If the HARQ decoding failure indication is transmitted in the U-plane (user plane), then it shall be timestamped with the CFN (connection frame number) plus subframe number when the last unsuccessful attempt to decode occurred;        Rule for choosing a transport bearer (i.e. a MAC-d flow, wherein MAC stands for medium access control) on which to send the failure indication. This is so because the MAC-d demultiplexing information is contained inband (i.e. within the MAC-e PDU) and is unknown to the Node B prior to successful decoding;        The case where MAC-d flows with different retransmission limits are multiplexed within the same MAC-e PDU (protocol data unit);        Optimisation of the SHO (soft handover) case (e.g. a means for resetting the retransmission counter in a Node B in case a MAC-e PDU was successfully received via another Node B).        